drivers/input/keyboard/qt1070.c

   1 /*
   2  *  Atmel AT42QT1070 QTouch Sensor Controller
   3  *
   4  *  Copyright (C) 2011 Atmel
   5  *
   6  *  Authors: Bo Shen <voice.shen@atmel.com>
   7  *
   8  *  Base on AT42QT2160 driver by:
   9  *  Raphael Derosso Pereira <raphaelpereira@gmail.com>
  10  *  Copyright (C) 2009
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or
  15  *  (at your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to the Free Software
  24  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/i2c.h>
  29 #include <linux/input.h>
  30 #include <linux/slab.h>
  31 #include <linux/irq.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/delay.h>
  35
  36 /* Address for each register */
  37 #define CHIP_ID            0x00
  38 #define QT1070_CHIP_ID     0x2E
  39
  40 #define FW_VERSION         0x01
  41 #define QT1070_FW_VERSION  0x15
  42
  43 #define DET_STATUS         0x02
  44
  45 #define KEY_STATUS         0x03
  46
  47 /* Calibrate */
  48 #define CALIBRATE_CMD      0x38
  49 #define QT1070_CAL_TIME    200
  50
  51 /* Reset */
  52 #define RESET              0x39
  53 #define QT1070_RESET_TIME  255
  54
  55 /* AT42QT1070 support up to 7 keys */
  56 static const unsigned short qt1070_key2code[] = {
  57         KEY_0, KEY_1, KEY_2, KEY_3,
  58         KEY_4, KEY_5, KEY_6,
  59 };
  60
  61 struct qt1070_data {
  62         struct i2c_client *client;
  63         struct input_dev *input;
  64         unsigned int irq;
  65         unsigned short keycodes[ARRAY_SIZE(qt1070_key2code)];
  66         u8 last_keys;
  67 };
  68
  69 static int qt1070_read(struct i2c_client *client, u8 reg)
  70 {
  71         int ret;
  72
  73         ret = i2c_smbus_read_byte_data(client, reg);
  74         if (ret < 0)
  75                 dev_err(&client->dev,
  76                         "can not read register, returned %d\n", ret);
  77
  78         return ret;
  79 }
  80
  81 static int qt1070_write(struct i2c_client *client, u8 reg, u8 data)
  82 {
  83         int ret;
  84
  85         ret = i2c_smbus_write_byte_data(client, reg, data);
  86         if (ret < 0)
  87                 dev_err(&client->dev,
  88                         "can not write register, returned %d\n", ret);
  89
  90         return ret;
  91 }
  92
  93 static bool qt1070_identify(struct i2c_client *client)
  94 {
  95         int id, ver;
  96
  97         /* Read Chip ID */
  98         id = qt1070_read(client, CHIP_ID);
  99         if (id != QT1070_CHIP_ID) {
 100                 dev_err(&client->dev, "ID %d not supported\n", id);
 101                 return false;
 102         }
 103
 104         /* Read firmware version */
 105         ver = qt1070_read(client, FW_VERSION);
 106         if (ver < 0) {
 107                 dev_err(&client->dev, "could not read the firmware version\n");
 108                 return false;
 109         }
 110
 111         dev_info(&client->dev, "AT42QT1070 firmware version %x\n", ver);
 112
 113         return true;
 114 }
 115
 116 static irqreturn_t qt1070_interrupt(int irq, void *dev_id)
 117 {
 118         struct qt1070_data *data = dev_id;
 119         struct i2c_client *client = data->client;
 120         struct input_dev *input = data->input;
 121         int i;
 122         u8 new_keys, keyval, mask = 0x01;
 123
 124         /* Read the detected status register, thus clearing interrupt */
 125         qt1070_read(client, DET_STATUS);
 126
 127         /* Read which key changed */
 128         new_keys = qt1070_read(client, KEY_STATUS);
 129
 130         for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) {
 131                 keyval = new_keys & mask;
 132                 if ((data->last_keys & mask) != keyval)
 133                         input_report_key(input, data->keycodes[i], keyval);
 134                 mask <<= 1;
 135         }
 136         input_sync(input);
 137
 138         data->last_keys = new_keys;
 139         return IRQ_HANDLED;
 140 }
 141
 142 static int qt1070_probe(struct i2c_client *client,
 143                                 const struct i2c_device_id *id)
 144 {
 145         struct qt1070_data *data;
 146         struct input_dev *input;
 147         int i;
 148         int err;
 149
 150         err = i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE);
 151         if (!err) {
 152                 dev_err(&client->dev, "%s adapter not supported\n",
 153                         dev_driver_string(&client->adapter->dev));
 154                 return -ENODEV;
 155         }
 156
 157         if (!client->irq) {
 158                 dev_err(&client->dev, "please assign the irq to this device\n");
 159                 return -EINVAL;
 160         }
 161
 162         /* Identify the qt1070 chip */
 163         if (!qt1070_identify(client))
 164                 return -ENODEV;
 165
 166         data = kzalloc(sizeof(struct qt1070_data), GFP_KERNEL);
 167         input = input_allocate_device();
 168         if (!data || !input) {
 169                 dev_err(&client->dev, "insufficient memory\n");
 170                 err = -ENOMEM;
 171                 goto err_free_mem;
 172         }
 173
 174         data->client = client;
 175         data->input = input;
 176         data->irq = client->irq;
 177
 178         input->name = "AT42QT1070 QTouch Sensor";
 179         input->dev.parent = &client->dev;
 180         input->id.bustype = BUS_I2C;
 181
 182         /* Add the keycode */
 183         input->keycode = data->keycodes;
 184         input->keycodesize = sizeof(data->keycodes[0]);
 185         input->keycodemax = ARRAY_SIZE(qt1070_key2code);
 186
 187         __set_bit(EV_KEY, input->evbit);
 188
 189         for (i = 0; i < ARRAY_SIZE(qt1070_key2code); i++) {
 190                 data->keycodes[i] = qt1070_key2code[i];
 191                 __set_bit(qt1070_key2code[i], input->keybit);
 192         }
 193
 194         /* Calibrate device */
 195         qt1070_write(client, CALIBRATE_CMD, 1);
 196         msleep(QT1070_CAL_TIME);
 197
 198         /* Soft reset */
 199         qt1070_write(client, RESET, 1);
 200         msleep(QT1070_RESET_TIME);
 201
 202         err = request_threaded_irq(client->irq, NULL, qt1070_interrupt,
 203                                    IRQF_TRIGGER_NONE | IRQF_ONESHOT,
 204                                    client->dev.driver->name, data);
 205         if (err) {
 206                 dev_err(&client->dev, "fail to request irq\n");
 207                 goto err_free_mem;
 208         }
 209
 210         /* Register the input device */
 211         err = input_register_device(data->input);
 212         if (err) {
 213                 dev_err(&client->dev, "Failed to register input device\n");
 214                 goto err_free_irq;
 215         }
 216
 217         i2c_set_clientdata(client, data);
 218
 219         /* Read to clear the chang line */
 220         qt1070_read(client, DET_STATUS);
 221
 222         return 0;
 223
 224 err_free_irq:
 225         free_irq(client->irq, data);
 226 err_free_mem:
 227         input_free_device(input);
 228         kfree(data);
 229         return err;
 230 }
 231
 232 static int qt1070_remove(struct i2c_client *client)
 233 {
 234         struct qt1070_data *data = i2c_get_clientdata(client);
 235
 236         /* Release IRQ */
 237         free_irq(client->irq, data);
 238
 239         input_unregister_device(data->input);
 240         kfree(data);
 241
 242         return 0;
 243 }
 244
 245 #ifdef CONFIG_PM_SLEEP
 246 static int qt1070_suspend(struct device *dev)
 247 {
 248         struct i2c_client *client = to_i2c_client(dev);
 249         struct qt1070_data *data = i2c_get_clientdata(client);
 250
 251         if (device_may_wakeup(dev))
 252                 enable_irq_wake(data->irq);
 253
 254         return 0;
 255 }
 256
 257 static int qt1070_resume(struct device *dev)
 258 {
 259         struct i2c_client *client = to_i2c_client(dev);
 260         struct qt1070_data *data = i2c_get_clientdata(client);
 261
 262         if (device_may_wakeup(dev))
 263                 disable_irq_wake(data->irq);
 264
 265         return 0;
 266 }
 267 #endif
 268
 269 static SIMPLE_DEV_PM_OPS(qt1070_pm_ops, qt1070_suspend, qt1070_resume);
 270
 271 static const struct i2c_device_id qt1070_id[] = {
 272         { "qt1070", 0 },
 273         { },
 274 };
 275 MODULE_DEVICE_TABLE(i2c, qt1070_id);
 276
 277 static struct i2c_driver qt1070_driver = {
 278         .driver = {
 279                 .name   = "qt1070",
 280                 .pm     = &qt1070_pm_ops,
 281         },
 282         .id_table       = qt1070_id,
 283         .probe          = qt1070_probe,
 284         .remove         = qt1070_remove,
 285 };
 286
 287 module_i2c_driver(qt1070_driver);
 288
 289 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
 290 MODULE_DESCRIPTION("Driver for AT42QT1070 QTouch sensor");
 291 MODULE_LICENSE("GPL");